Robert Koch bigraphy, stories - German physician and bacteriologist

Robert Koch : biography

11 December 1843 - 27 May 1910

Robert Heinrich Herman Koch (December 11, 1843 – May 27, 1910), considered to be the founder of modern bacteriology, is known for his role in identifying the specific causative agents of tuberculosis, cholera, and anthrax and for giving experimental support for the concept of infectious disease."Robert Koch." World of Microbiology and Immunology. Ed. Brenda Wilmoth Lerner and K. Lee Lerner. Detroit: Gale, 2006. Biography In Context. Web. 14 Apr. 2013. In addition to his pioneering studies on these diseases, Koch created and improved significant laboratory technologies and techniques in the field of microbiology, and made a number of key discoveries pertaining to public health."Brock, Thomas. Robert Koch: A life in medicine and bacteriology. ASM Press: Washington DC, 1999. Print. His research led to the creation of Koch’s postulates, a series of four generalized principles linking specific microorganisms to particular diseases which remain today the “gold standard” in medical microbiology. As a result of his groundbreaking research on tuberculosis, Koch received the Nobel Prize in Physiology or Medicine in 1905.

Research contributions

Anthrax

Robert Koch is widely-known for his work with anthrax, discovering the causative agent of the fatal disease to be Bacillus anthracis."Germ theory of disease." World of Microbiology and Immunology. Ed. Brenda Wilmoth Lerner and K. Lee Lerner. Detroit: Gale, 2007. Biography In Context. Web. 14 Apr. 2013. Koch discovered spore formation in the anthrax bacteria, which could remain dormant under specific conditions. However, under optimal conditions, he found that the spores were activated and caused disease. To determine this causative agent, he dry-fixed bacterial cultures onto glass slides, used dyes to stain the cultures, and then observed them through a microscope. Koch’s work with anthrax is notable in that he was the first to link a particular microorganism with a given disease, rejecting the idea of spontaneous generation and proving the germ theory of disease.

Koch's Four Postulates

Koch accepted a position as government advisor with the Imperial Department of Health in 1880.O’Connor, T.M. “Tuberculosis, Overview.” International Encyclopedia of Public Health. 2008. Web. During his time as government advisor, he published a report in which he stated the importance of pure cultures in isolating disease-causing organisms and explained the necessary steps to obtain these cultures, methods which are summarized in Koch’s four postulates.Amsterdamska, Olga. “Bacteriology, Historical.” International Encyclopedia of Public Health. 2008. Web. Koch’s discovery of the causative agent of anthrax led to the formation of a generic set of postulates which can be used in the determination of the cause of any infectious disease. These postulates, which not only outlined a method for linking cause and effect of an infectious disease but also established the significance of laboratory culture of infectious agents, are listed here: 1. The organism must always be present, in every case of the disease. 2. The organism must be isolated from a host containing the disease and grown in pure culture. 3. Samples of the organism taken from pure culture must cause the same disease when inoculated into a healthy, susceptible animal in the laboratory. 4. The organism must be isolated from the inoculated animal and must be identified as the same original organism first isolated from the originally diseased host.

Isolating pure culture on solid media

Koch began conducting research on microorganisms in a laboratory that was connected to his patient examination room. Koch’s early research in this laboratory proved to yield one of his major contributions to the field of microbiology, as it was there that he developed the technique of growing bacteria. Koch's second postulate calls for the isolation and growth of a selected pathogen in pure laboratory culture.Madigan, Michael T., et al. Brock Biology of Microorganisms: Thirteenth edition. Benjamin Cummings: Boston, 2012. Print. In an attempt to grow bacteria, Koch began to use solid nutrients such as potato slices. Through these initial experiments, Koch observed individual colonies of identical, pure cells. Coming to the conclusion that potato slices were not suitable media for all organisms, Koch later began to use nutrient solutions with gelatin. However, he soon realized that gelatin, like potato slices, was not the optimal medium for bacterial growth, as it did not remain solid at 37˚C, the ideal temperature for growth of most human pathogens. Therefore, Koch eventually began to utilize agar to grow and isolate pure cultures, as this polysaccharide remains solid at 37˚C, is not degraded by most bacteria, and results in a transparent medium.

Living octopus

Living octopus

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